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Diffstat (limited to 'math/math-underflow.h')
| -rw-r--r-- | math/math-underflow.h | 79 |
1 files changed, 79 insertions, 0 deletions
diff --git a/math/math-underflow.h b/math/math-underflow.h new file mode 100644 index 0000000000..c5e5c79768 --- /dev/null +++ b/math/math-underflow.h @@ -0,0 +1,79 @@ +/* Check for underflow and force underflow exceptions. + Copyright (C) 2015-2018 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <http://www.gnu.org/licenses/>. */ + +#ifndef _MATH_UNDERFLOW_H +#define _MATH_UNDERFLOW_H 1 + +#include <float.h> +#include <math.h> + +#include <math-barriers.h> + +#define fabs_tg(x) __MATH_TG ((x), (__typeof (x)) __builtin_fabs, (x)) + +/* These must be function-like macros because some __MATH_TG + implementations macro-expand the function-name argument before + concatenating a suffix to it. */ +#define min_of_type_f() FLT_MIN +#define min_of_type_() DBL_MIN +#define min_of_type_l() LDBL_MIN +#define min_of_type_f128() FLT128_MIN + +#define min_of_type(x) __MATH_TG ((x), (__typeof (x)) min_of_type_, ()) + +/* If X (which is not a NaN) is subnormal, force an underflow + exception. */ +#define math_check_force_underflow(x) \ + do \ + { \ + __typeof (x) force_underflow_tmp = (x); \ + if (fabs_tg (force_underflow_tmp) \ + < min_of_type (force_underflow_tmp)) \ + { \ + __typeof (force_underflow_tmp) force_underflow_tmp2 \ + = force_underflow_tmp * force_underflow_tmp; \ + math_force_eval (force_underflow_tmp2); \ + } \ + } \ + while (0) +/* Likewise, but X is also known to be nonnegative. */ +#define math_check_force_underflow_nonneg(x) \ + do \ + { \ + __typeof (x) force_underflow_tmp = (x); \ + if (force_underflow_tmp \ + < min_of_type (force_underflow_tmp)) \ + { \ + __typeof (force_underflow_tmp) force_underflow_tmp2 \ + = force_underflow_tmp * force_underflow_tmp; \ + math_force_eval (force_underflow_tmp2); \ + } \ + } \ + while (0) +/* Likewise, for both real and imaginary parts of a complex + result. */ +#define math_check_force_underflow_complex(x) \ + do \ + { \ + __typeof (x) force_underflow_complex_tmp = (x); \ + math_check_force_underflow (__real__ force_underflow_complex_tmp); \ + math_check_force_underflow (__imag__ force_underflow_complex_tmp); \ + } \ + while (0) + +#endif /* math-underflow.h */ |